In interior/exterior materials for household appliances or buildings, there is strong demand for films providing a metallic visual effect for interior decoration. Although actually made of resins and thus inexpensive and easy to handle, such films appear to be made of metal, such as expensive stainless steel.
To this end, fine cracks are formed on a surface of the film, as seen on a surface of metal such as stainless steel. In addition, the film is required to have a metallic color, which seems to result, not from coatings, but from original materials.
For example, Korean Patent Publication No. 10-2006-0078530 A discloses a high gloss sheet for providing a metallic effect, which includes a PET film having hairline patterns, wherein, under the hairline patterns, a primer layer, an aluminum-deposited layer, a urethane adhesive layer, and a thermoplastic resin layer are sequentially formed.
However, in a conventional method wherein a surface of a film is scratched to form hairlines, i.e. fine cracks during passing through a sandpaper roll, although it is possible to form hairlines in a length direction of the film, i.e. in a longitudinal direction, hairlines are difficult to form in a width direction of the film, i.e. in a transverse direction. Thus, the film has only vertical hairlines, thereby making it difficult to realize natural-looking patterns as in metal.
Through studies aimed at providing a more natural metallic appearance, the inventors found that a film having a realistic metallic appearance can be manufactured using inventive embossing rolls, and completed the present invention.